OSP CHEMISTRY

Organic Solderability Preservatives (OSPs), also known as anti-tarnish, on bare copper printed circuit boards (PCBs) are becoming more prevalent in the electronics industry as the low-cost replacement to Hot Air Solder Leveling (HASL). Introducing the anti-tarnish alternative into the customer sites requires working closely with the coating supplier, assembler, and Original Equipment Manufacturer (OEM) to gain a mutual understanding of respective processing concerns and finished product requirements. An operational cost comparison was completed at Merix Corporation (formerly Tektronix Circuit Board Division) detailing the annual expenses associated with the HASL process versus an in-line anti-tarnish
organic protective coating line. The results of this study revealed that the OSP process is approximately one-third the cost of the HASL process. An implementation plan, designed jointly by the board shop and assembly customers, was used for the selection of the OSP chemistry supplier and introduction of the bare copper process into multiple customer sites.
Presented will be a PCB fabrication cost comparison of HASL versus OSP, a method of introducing the technology and products into the customer site, and managing the conversion through information sharing. The presented OSP technology is based on the newly introduced substituted benzimidazolebased compounds.